Electron discharge device



Dec. 1, 1936.

C. E. FAY

ELECTRON DISCHARGE (DEVICE Filed NOV. 1, 1934 INVENTOR C. 5. FA Y ATTORNEY Patented Dec. 1, 1936 ELECTRON DISCHARGE DEVICE Clifford E. Fay, Chatham,"N. 'J., assignor to Bell Telephone Laboratories,

Incorporated; New.

York, N. Y., a corporation of New York Application November 1, 1934, :Serial No. 750,920

6 Claims.

This invention relates to electron discharge devices and more particularly tosuch devices of the shielded grid type adapted for the amplification of ultra-high frequency impulses.

One object of this invention is to amplifyefiiciently currents and voltages of ultra-high frequencies.

Another object of thisinvention is to shield effectively-the input electrode and terminalsof an electron discharge device from .the output electrode and terminals.

Still another object of this invention is to expedite the electricalassociation of the electrodes in electron discharge devices having a plurality of individual electrode units within a single enclosing vessel.

In one embodiment of this invention, an electron discharge device comprises an enclosing vessel having a plurality of pentode units therein,

39 each unit including a cathode, an anode, a control grid between the cathode and anode, and a shield grid and a suppressor grid disposed between the control grid and the anode. The control grids of the several units are individually mounted on metallic members or rods supported from a wall of the enclosing vessel. The anodes also are individually supported from the opposite wall of the vessel. .The suppressorgrids are electrically connected and mounted bya metallic J member or rod supported from the same wall as the control grid support members. The shield grids are mounted on a single metallic plate or disc extending across one end of the electrode units and to immediately adjacent walls of the r, enclosing vessel, the plate or disc serving to screen the control grid supports and terminals from the anode supports and terminals. In order to further shield the control grid terminals from the anode terminals, an external metallic member is provided which surrounds the enclosing vessel andis disposed substantially coplanar with the plate or disc supporting the shield grids.

' The invention and the features thereof will be understood more clearly and fully from the following detailed description with reference to the accompanying drawing in which:

Fig. l is a perspective view of an electron discharge device illustrative of this invention, portions of the enclosing vessel and of the anode of one electrode unit being broken away to show structural details more clearly;

Fig. 2 is an end view of one of the electrode units *showing the configuration and disposition of the electrodes;

in a cylindrical boundary about the respective Fig. 3 is an enlarged detail wiewofthe cathode :of each of the electrodeunits;

Fig. 4 is an enlarged-detailview of thecontrol 'grid and the supports therefor; and i s Fig. 5 is another enlarged detailview showing the association of the screen grid electrode :and thevplate or disc support therefor. 1

Referring now to the drawing,'the electrondischarge device comprises "an -enclosing vessel 10 having end walls H and I2 andenclosingrtwo pentode units. Each of the pentode units includes an incandescible cathode I 3, a control grid M, a shield grid 15, a suppressor grid 16, and an anode H, the two units being disposed with their longitudinal axes parallel. each Fllllit preferably are positioned as-closely together as is mechanically and electrically feasible.

Each cathode 13 comprises a helix, I 8, which maybe ofwth'criated tungsten,;secured at'one end to a tie member l9 extending from a'wireor 0 rod 20 sealed in the end wall ll of the enclosing vessel. Preferably, the tie members 19 are resilient so that'a slighttension is appliedto'the helices :13 and their linear form is maintained. The two cathodes are supported at the other end from a wire or srod-ZI secured to-a support 22 also sealed in the end wall 1! ofithe enclosing vessel. 1

Each of thecontrol grids comprises a pair'of cylindrical metallic end members or collars 123 and i l, betweenwhich a plurality of 'wires'i25 'extend, the wires being secured to the end members or collars'as by welding. The wires 25 .are'idisposed parallel to one another and are arranged;

cathodes. A- metallic wireor stripi26 is secured to the end member or'collar'23, andito -a short rigid wire'21'which'is secured in turnito asup- :Vport wire or rod :28 sealed in the end-wall l-l ch 2 secureiiito:tthelzcath'ode support rod 22APrferably, in the operation of the device, the cathode 55 The :electrodes vin 15 .of the device. with suitable apertures through which the cathrespect to a corresponding cathode. parallel wires 4| of each group are secured to a support rod 22 is connected to the negative pole of the source of cathode heating current so that the suppressor grids are maintained at substantially zero potential with respect to the other rids and the anode.

The anodes comprise a plurality of arcuate sections 34 each provided with large surface flanges 35. Corresponding flanges on adjacent sections are secured together in face to face relation, as by welding, to provide a cylindrical portion which is disposed about the corresponding suppressor grid and coaxialtherewith and with the corresponding cathode. The flanges 35 preferably are made as large as is feasible in order to effectively dissipate heat from the electrodes during operation of the device. As clearly shown shown in Fig. 2, two pairs of the flanges on each anode are bent outwardly so that the heat will be radiated away from the electrode units toward the side walls of the enclosing vessel. Each anode 'is supported by a rigid wire or rod 36 secured to one of the flanges 35 and sealed in the end wall 12 of the enclosing vessel.

A metallic plate or disc 31 is supported by a pair of wires or rods 38 sealed in the end wall H of the enclosing vessel and extends across one end of the electrode units and to immediately adjacent the side walls of the enclosing vessel i0. Preferably, the plate or disc is provided with a turned edge or peripheral flange 39 to prevent distortion thereof by heat during the operation The plate or disc 31 is provided ode rods 20 and 22 and the control grid rods 28 pass. It is provided also with apertures 40 for allowing passage of two groups of parallel wires 4| which carry helical shield or screen grids 42. As clearly shown in Fig. 2, each of the screen grids 42 is disposed between a corresponding control grid and suppressor grid and coaxially with Two of the cross rod or wire 43 lying on and secured to one surface of the disc or plate 31 and connected to one of the support rods or wires 38 by a wire stub 44.

The disc or plate 31 effectively segregates and shields the input conductors of the device from the anode conductors 36 so that the device may be operated at very high frequencies. In order to insure further and substantially complete shielding, the device may be mounted on a metallic partition or external shield 45 which is disposed substantially coplanar with the disc or plate 31.

Although a specific embodiment of the invention has been shown and described, it is to be understood, of course, that modifications may be made therein without departing from the scope and spirit of this invention as defined in the appended claims.

.end of said enclosing vessel, leading-in conductors for said cathode and one of said grid electrodes extending through the opposite end of said enclosing vessel, a, metallic shield posi-.

tioned between said ends and at substantially right angles to the longitudinal axis of said grid electrodes, said shield being electrically connected to and supporting another of said grid electrodes, and a single leading-in conductor supporting said shield from said opposite end of said vessel.

2. An electron discharge device comprising an enclosing vessel, a plurality of electrode units within said enclosing vessel, said units being disposed with their longitudinal axes substantially parallel and each including a cathode, an anode, and a grid electrode cooperatively disposed with respect to said cathode and anode, leading in conductors for said anodes extending from one end of said vessel, leading in conductors for said grids extending from said vessel at points remote from said one end, and a metallic disc extending adjacent one end of said units and supporting said grid electrodes, said disc shielding said grid conductors from said anode conductors.

3. An electron discharge device comprising an enclosing vessel, a metallic shield extending across said vessel and to immediately adjacent walls thereof and dividing it into two compartments, an electrode assembly in one of said compartments including a cathode, an anode, a control electrode between said anode and cathode, and a shield electrode, said shield electrode being electrically coupled to said metallic shield and extending immediately thereadjacent, a leadingin conductor for said anode sealed in said enclosing vessel and disposed in said one comparti ment, and supporting means for said control electrode disposed in the other compartment, said supporting means serving as a leading-in conductor.

4. An electron discharge device comprising an enclosing vessel, a cathode, an anode, a control electrode, a leading-in conductor for said anode extending through one end of said enclosing vessel, a leading-in conductor for said control electrode extending through the opposite end of said enclosing vessel, a metallic shield extending across one end of said anode and control electrode and to immediately adjacent lateral walls of said vessel whereby said conductor for said control electrode is electrically segregated from said anode and the leading-in conductor therefor, a support suspended from and carried by said shield, and a screen electrode carried by said support.

5. An electron discharge device comprising a plurality of electrode units each including a cathode, an anode, and a plurality of grid electrodes intermediate said cathode and said anode, means electrically connecting one grid electrode of one unit with the corresponding grid electrode of another unit, a support secured to said means, a disc extending across one end of said electrode units and supporting other corresponding of said grid electrodes, and a support for said disc.

6. An electron discharge device comprising a plurality of electrode units each including a cathode, a control electrode, a screen electrode, a suppressor electrode, and an anode, leading-in conductors individually supporting said control electrodes, a single leading-in conductor supporting said suppressor electrodes, leading-in conductors individually supporting said anodes, and means including a metallic disc supporting and electrically connecting said screen electrodes, said disc shielding the leading-in conductors for said control electrodes from the leading-in conductors for said anodes.

CLIFFORD E. FAY. 

